I've flocked bits and pieces of the inside of my OTA (opposite the focuser and down around the mirror), but I used a fairly thick felt and some adhesive that didn't really work very well.
So the end result, is a pretty messy job (though it still works ok). I want to clean it up and do the whole tube.
After seeing Dave47Tuc's excellent flocking job at Snake Valley, this thread is specifically for him, to tell me:
a) What material he used
b) What adhesive he used
c) How much they were
b) Where he bought them from
So Dave, take it away
Looking into his tube, there was zero light reflection and it looked great.
Mike you need to get those adhesive backed felt from Bunning's or Mitre 10. They used to have some pretty good stuff but lately I have not been able to find them (maybe someone else might know where to find these). I got some Protostar flock paper from the states and they are a shocker. They don't stick down very well when overlapped so my flock is quite messy as well. But I like to think of the wrinkles as offering additional baffling
If you go to one of the big art supply shops you can get black flock paper. It is really inky black when stuck inside an optical tube . I used it once inside the focusser and eyepiece barrels of a 6 inch refractor.I used double sided tape to secure it .
philip
THe flocking I used is noticably darker than Daves, but being a vinyl based product with some stretch in it had caused it to let go in some placed
I got mine from Bunnings but its no longer available .
I found this link http://tinyurl.com/bzbv7 in a discussion in the C9.25 Yahoo Groups. It points to a flocking thread on sci.astro.amateur in which luminaries such as Roland Christen (Astro-Physics) made comments. Well worth a read (if the link still works!).
Cheers
Dennis
PS - to whet your appetite, here is an excerpt from that thread which spawned some quite interesting discussions.
Start copy+++++++++++++++++
"Flocking doesn't change the sharpness of the optics, does not eliminate
any optical aberrations, does not smooth out rough surface finish, does not
reduce the central obstruction, etc. These are the primary things that affect
planetary contrast. Flocking does affect the ability to see faint deep sky
objects in light polluted skies, but again does not help any in really dark
skies. Planets are so bright with respect to the background sky, that it makes
virtually no difference if baffles are there or not. The light from the planet
is blocked from coming directly into the eyepiece by the secondary mirror, and any light that does come in on the side from the background sky does not have enough brightness to register with respect to the planet itself."
End copy+++++++++++++++++++
Last edited by Dennis; 07-11-2005 at 02:15 PM.
Reason: Added the PS text.
Gee I dont know that flocking does not help in really dark sky. I "invented" a long dew tube with 8 baffles (2.5 feet) in an effort to reduce stray star light entering the tube for my 150ar and it made a noticable difference in my dark sky. The tube inside in not flocked yet (cant find the stuff locally) but I recon that will improve things more.
alex
I found this link http://tinyurl.com/bzbv7 in a discussion in the C9.25 Yahoo Groups. It points to a flocking thread on sci.astro.amateur in which luminaries such as Roland Christen (Astro-Physics) made comments. Well worth a read (if the link still works!).
Cheers
Dennis
PS - to whet your appetite, here is an excerpt from that thread which spawned some quite interesting discussions.
Start copy+++++++++++++++++
"Flocking doesn't change the sharpness of the optics, does not eliminate
any optical aberrations, does not smooth out rough surface finish, does not
reduce the central obstruction, etc. These are the primary things that affect
planetary contrast. Flocking does affect the ability to see faint deep sky
objects in light polluted skies, but again does not help any in really dark
skies. Planets are so bright with respect to the background sky, that it makes
virtually no difference if baffles are there or not. The light from the planet
is blocked from coming directly into the eyepiece by the secondary mirror, and any light that does come in on the side from the background sky does not have enough brightness to register with respect to the planet itself."
End copy+++++++++++++++++++
All those points are correct, but they left out the most important one! (well for high res imaging, is there anything else? ) Flocking isolates the air from your tube so that "supercooling" of the metal tube under the night sky won't cause waterfalls of cold air to start running down inside your scope and across the mirror.
It also (slightly) reduces the ability of the air inside the tube to lose heat as it's no longer in direct contact with the metal, but for people with open ended tubes this isn't a problem anyway.
I'm very happy with the results on my tube, I bought adhesive black felt from one of the craft stores, but in hindsight the mitre10/bunnings idea sounds like the better one. Felt does shed a little when you first put it in the tube, but that stops after w hile when all the loose fibres have come out.
The tube inside in not flocked yet (cant find the stuff locally) but I recon that will improve things more.
alex
I'm not certain, but you could try Bunnings in Lismore. Prolly the nearest for
you/us next time I'm over there I'll be dropping in to have a look. Not sure
when that will be, haven't been there for a few months lol
Hi Guys, I found that "spotlight" has it in rolls of 1 mtr wide and any length you need, and with a VERY sticky adhesive backing, So you had better make sure you place it where you want it to be.
I was thinking about flocking the inside of my OTA this weekend to give me something to do (yer, like I dont have enough already ). Where did you end up getting your felt from Ice? Do the different flocking materials people use differ in any major way? I havent seen any so Im guessing its just thin felt with a sticky back? Id rather not use spray on adhesive as its shocking stuff to work with.
John: did you find out what Spotlight call their product? If I know in advance it will save me sounding like a dork trying to explain myself.
Yep that would work too.. that's 1 sheet of stuff I bought from Lincraft a few months ago as a test, it's more of a felty material whereas the new roll I bought is a suedey material.
They're both almost exactly the same cost.. the lincraft one comes in squares, the mitre10 one came in a roll.
It is self adhesive.
) Flocking isolates the air from your tube so that "supercooling" of the metal tube under the night sky won't cause waterfalls of cold air to start running down inside your scope and across the mirror.
I think 2.5 metres did the job. I got 4 metres but have over 1 metre left over.
). Where did you end up getting your felt from Ice? Do the different flocking materials people use differ in any major way? I havent seen any so Im guessing its just thin felt with a sticky back? Id rather not use spray on adhesive as its shocking stuff to work with.
